Stabilization of polyurethane foam polyol premixes containing halogenated olefin blowing agents

ABSTRACT

The invention provides polyurethane and polyisocyanurate foams and methods for the preparation thereof More particularly, the invention relates to open-celled, polyurethane and polyisocyanurate foams and methods for their preparation. The foams are characterized by a fine uniform cell structure and little or no foam collapse. The foams are produced with a polyol premix composition which comprises a combination of a hydrohaloolefin blowing agent, a polyol, a silicone surfactant, and a catalyst which is an adduct of an amine and an organic acid.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of co-pending Provisional patentapplication Ser. No. 60/979,427 filed Oct. 12, 2007, which isincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to polyurethane and polyisocyanuratefoams and methods for the preparation thereof. More particularly, theinvention relates to rigid, polyurethane and polyisocyanurate foams andmethods for their preparation, which foams are characterized by a fineuniform cell structure and little or no foam collapse. The foams areproduced with an organic polyisocyanate and a polyol premix compositionwhich comprises a combination of a blowing agent, which is preferably ahydrohaloolefin, a polyol, a silicone surfactant, and a catalyst whichcatalyst is an adduct of an amine and an organic acid.

2. Description of the Related Art

The class of foams known as low density, rigid polyurethane orpolyisocyanurate foams has utility in a wide variety of insulationapplications including roofing systems, building panels, buildingenvelope insulation, refrigerators and freezers. A critical factor inthe large-scale commercial acceptance of rigid polyurethane foams hasbeen their ability to provide a good balance of properties. Rigidpolyurethane and polyisocyanurate foams are known to provide outstandingthermal insulation, excellent fire resistance properties, and superiorstructural properties at reasonably low densities. The foam industry hashistorically used liquid fluorocarbon blowing agents because of theirease of use in processing conditions. Fluorocarbons not only act asblowing agents by virtue of their volatility, but also are encapsulatedor entrained in the closed cell structure of the rigid foam and are themajor contributor to the low thermal conductivity properties of therigid urethane foams. The use of a fluorocarbon as the preferredcommercial expansion or blowing agent in insulating foam applications isbased in part on the resulting k-factor associated with the foamproduced. The k-factor is defined as the rate of transfer of heat energyby conduction through one square foot of one-inch thick homogenousmaterial in one hour where there is a difference of one degreeFahrenheit perpendicularly across the two surfaces of the material.Since the utility of closed-cell polyurethane-type foams is based, inpart, on their thermal insulation properties, it would be advantageousto identify materials that produce lower k-factor foams.

It is known in the art to produce rigid polyurethane andpolyisocyanurate foams by reacting a polyisocyanate with a polyol in thepresence of a blowing agent, a catalyst, a surfactant and optionallyother ingredients. Blowing agents include hydrocarbons, fluorocarbons,chlorocarbons, fluorochlorocarbons, halogenated hydrocarbons, ethers,esters, aldehydes, ketones, or CO₂ generating materials. Heat generatedwhen the polyisocyanate reacts with the polyol, and volatilizes theblowing agent contained in the liquid mixture, thereby forming bubblestherein. As the polymerization reaction proceeds, the liquid mixturebecomes a cellular solid, entrapping the blowing agent in the foam'scells. If a surfactant is not used in the foaming composition, thebubbles simply pass through the liquid mixture without forming a foam orforming a foam with large, irregular cells rendering it not useful.Preferred blowing agents have low global warming potential. Among theseare hydrohaloolefins including hydrohaloolefins (HFOs) of whichtrans-1,3,3,3-tetrafluoropropene (HFO-1234ze) is of particular interestand hydrochlorofluoroolefins (HFCOs) of which1-chloro-3,3,3-trifluoropropene (HFCO-1233zd) is of particular interest.Processes for the manufacture of 1,3,3,3-tetrafluoropropene aredisclosed in U.S. Pat. Nos. 7,230,146 and 7,189,884. Processes for themanufacture of 1-chloro-3,3,3-trifluoropropene are disclosed in U.S.Pat. Nos. 6,844,475 and 6,403,847.

It is convenient in many applications to provide the components forpolyurethane or polyisocyanurate foams in pre-blended formulations. Mosttypically, the foam formulation is pre-blended into two components. Thepolyisocyanate and optional isocyanate compatible raw materials comprisethe first component, commonly referred to as the “A” component. A polyolor mixture of polyols, surfactant, catalyst, blowing agent, and otherisocyanate reactive and non-reactive components comprise the secondcomponent, commonly referred to as the “B” component. Accordingly,polyurethane or polyisocyanurate foams are readily prepared by bringingtogether the A and B side components either by hand mix for smallpreparations and, preferably, machine mix techniques to form blocks,slabs, laminates, pour-in-place panels and other items, spray appliedfoams, froths, and the like. Optionally, other ingredients such as fireretardants, colorants, auxiliary blowing agents, and other polyols canbe added to the mixing head or reaction site. Most conveniently,however, they are all incorporated into one B component.

A shortcoming of two-component systems, especially those using certainhydrohaloolefins, including HFO-1234ze and HFCO-1233zd is the shelf-lifeof the B-side composition. Normally when a foam is produced by bringingtogether the A and B side components, a good foam is obtained. However,if the polyol premix composition is aged, prior to treatment with thepolyisocyanate, the foams are of lower quality and may even collapseduring the formation of the foam.

It has now been found that the origin of the problem is the reaction ofcertain amine catalysts with certain hydrohaloolefins includingHFO-1234ze and HFCO-1233zd, resulting in partial decomposition of theblowing agent. It has been found that, subsequent to the decompositionof the blowing agent, the molecular weight of the polymeric siliconesurfactants, if present, is detrimentally altered, leading to poor foamstructure.

While it is possible to solve the problem by separating the blowingagent, surfactant, and catalyst, for example by adding the blowingagent, amine catalyst, or surfactant to the polyisocyanate, (“A”component) or by introducing the blowing agent, amine catalyst, orsurfactant using a separate stream from the “A” or “B” component, apreferred solution is one that does not require reformulation or achange in the way the foams are made. It has now been found that acatalyst which is an adduct of an amine and an organic acid has lowerreactivity toward certain blowing agents, such as hydrohaloolefinsincluding trans-HFO-1234ze and HFCO-1233zd, such that good quality foamscan be produced even if the polyol blend has been aged.

DESCRIPTION OF THE INVENTION

The invention provides polyol premix composition which comprises acombination of a blowing agent, a polyol, a silicone surfactant, and acatalyst which catalyst is an adduct of an amine and an organic acid,wherein the blowing agent comprises a hydrohaloolefin, and optionally ahydrocarbon, fluorocarbon, chlorocarbon, fluorochlorocarbon, halogenatedhydrocarbon, CO₂ generating material, or combinations thereof.

The invention also provides a method of preparing a polyurethane orpolyisocyanurate foam comprising reacting an organic polyisocyanate withthe polyol premix composition.

The blowing agent component comprises a hydrohaloolefin, preferablycomprising at least one of trans-HFO-1234ze and HFCO-1233zd., andoptionally a hydrocarbon, fluorocarbon, chlorocarbon,fluorochlorocarbon, halogenated hydrocarbon, ether, fluorinated ether,ester, aldehyde, ketone, CO₂ generating material, or combinationsthereof.

The hydrohaloolefin preferably comprises at least one halooalkene suchas a fluoroalkene or chloroalkene containing from 3 to 4 carbon atomsand at least one carbon-carbon double bond. Preferred hydrohaloolefinsnon-exclusively include trifluoropropenes, tetrafluoropropenes such as(HFO-1234), pentafluoropropenes such as (HFO-1225),chlorotrifloropropenes such as (HFO-1233), chlorodifluoropropenes,chlorotrifluoropropenes, chlorotetrafluoropropenes, and combinations ofthese. More preferred that the compounds of the present invention arethe tetrafluoropropene, pentafluoropropene, and chlorotrifloropropenecompounds in which the unsaturated terminal carbon has not more than oneF or Cl substituent. Included are 1,3,3,3-tetrafluoropropene(HFO-1234ze); 1,1,3,3-tetrafluoropropene; 1,2,3,3,3-pentafluoropropene(HFO-1225ye); 1,1,1-trifluoropropene; 1,1,1,3,3-pentafluoropropene(HFO-1225zc); 1,1,1,3,3,3-hexafluorobut-2-ene,1,1,2,3,3-pentafluoropropene (HFO-1225yc); 1,1,1,2,3-pentafluoropropene(HFO-1225yez); 1-chloro-3,3,3-trifluoropropene (HFCO-1233zd);1,1,1,4,4,4-hexafluorobut-2-ene or combinations thereof, and any and allstructural isomers, geometric isomers, or stereoisomers of each ofthese.

Preferred hydrohaloolefins have a Global Warming Potential (GWP) of notgreater than 150, more preferably not greater than 100 and even morepreferably not greater than 75. As used herein, “GWP” is measuredrelative to that of carbon dioxide and over a 100-year time horizon, asdefined in “The Scientific Assessment of Ozone Depletion, 2002, a reportof the World Meteorological Association's Global Ozone Research andMonitoring Project,” which is incorporated herein by reference.Preferred hydrohaloolefins also preferably have an Ozone DepletionPotential (ODP) of not greater than 0.05, more preferably not greaterthan 0.02 and even more preferably about zero. As used herein, “ODP” isas defined in “The Scientific Assessment of Ozone Depletion, 2002, Areport of the World Meteorological Association's Global Ozone Researchand Monitoring Project,” which is incorporated herein by reference.

Preferred optional blowing agents non-exclusively include water, formicacid, organic acids that produce CO₂ when they react with an isocyanate,hydrocarbons; ethers, halogenated ethers; pentafluorobutane;pentafluoropropane; hexafluoropropane; heptafluoropropane; trans-1,2dichloroethylene; methyl formate; 1-chloro-1,2,2,2-tetrafluoroethane;1,1-dichloro-1-fluoroethane; 1,1,1,2-tetrafluoroethane;1,1,2,2-tetrafluoroethane; 1-chloro 1,1-difluoroethane;1,1,1,3,3-pentafluorobutane; 1,1,1,2,3,3,3-heptafluoropropane;trichlorofluoromethane; dichlorodifluoromethane;1,1,1,3,3,3-hexafluoropropane; 1,1,1,2,3,3-hexafluoropropane;difluoromethane; difluoroethane; 1,1,1,3,3-pentafluoropropane;1,1-difluoroethane; isobutane; normal pentane; isopentane; cyclopentane,or combinations thereof. The blowing agent component is usually presentin the polyol premix composition in an amount of from about 1 wt. % toabout 30 wt. %, preferably from about 3 wt. % to about 25 wt. %, andmore preferably from about 5 wt. % to about 25 wt. %, by weight of thepolyol premix composition. When both a hydrohaloolefin and an optionalblowing agent are present, the hydrohaloolefin component is usuallypresent in the blowing agent component in an amount of from about 5 wt.% to about 90 wt. %, preferably from about 7 wt. % to about 80 wt. %,and more preferably from about 10 wt. % to about 70 wt. %, by weight ofthe blowing agent component; and the optional blowing agent is usuallypresent in the blowing agent component in an amount of from about 95 wt.% to about 10 wt. %, preferably from about 93 wt. % to about 20 wt. %,and more preferably from about 90 wt. % to about 30 wt. %, by weight ofthe blowing agent component.

The polyol component, which includes mixtures of polyols, can be anypolyol which reacts in a known fashion with an isocyanate in preparing apolyurethane or polyisocyanurate foam. Useful polyols comprise one ormore of a sucrose containing polyol; phenol, a phenol formaldehydecontaining polyol; a glucose containing polyol; a sorbitol containingpolyol; a methylglucoside containing polyol; an aromatic polyesterpolyol; glycerol; ethylene glycol; diethylene glycol; propylene glycol;graft copolymers of polyether polyols with a vinyl polymer; a copolymerof a polyether polyol with a polyurea; one or more of (a) condensed withone or more of (b):

(a) glycerine, ethylene glycol, diethylene glycol, trimethylolpropane,ethylene diamine, pentaerythritol, soy oil, lecithin, tall oil, palmoil, castor oil;

(b) ethylene oxide, propylene oxide, a mixture of ethylene oxide andpropylene oxide; or combinations thereof. The polyol component isusually present in the polyol premix composition in an amount of fromabout 60 wt. % to about 95 wt. %, preferably from about 65 wt. % toabout 95 wt. %, and more preferably from about 70 wt. % to about 90 wt.%, by weight of the polyol premix composition.

The polyol premix composition next contains a silicone surfactant. Thesilicone surfactant is used to form a foam from the mixture, as well asto control the size of the bubbles of the foam so that a foam of adesired cell structure is obtained. Preferably, a foam with smallbubbles or cells therein of uniform size is desired since it has themost desirable physical properties such as compressive strength andthermal conductivity. Also, it is critical to have a foam with stablecells which do not collapse prior to forming or during foam rise.

Silicone surfactants for use in the preparation of polyurethane orpolyisocyanurate foams are available under a number of trade names knownto those skilled in this art. Such materials have been found to beapplicable over a wide range of formulations allowing uniform cellformation and maximum gas entrapment to achieve very low density foamstructures. The preferred silicone surfactant comprises a polysiloxanepolyoxyalkylene block co-polymer. Some representative siliconesurfactants useful for this invention are Momentive's L-5130, L-5180,L-5340, L-5440, L-6100, L-6900, L-6980 and L-6988; Air Products DC-193,DC-197, DC-5582, and DC-5598; and B-8404, B-8407, B-8409 and B-8462 fromGoldschmidt AG of Essen, Germany. Others are disclosed in U.S. Pat. Nos.2,834,748; 2,917,480; 2,846,458 and 4,147,847. The silicone surfactantcomponent is usually present in the polyol premix composition in anamount of from about 0.5 wt. % to about 5.0 wt. %, preferably from about1.0 wt. % to about 4.0 wt. %, and more preferably from about 1.5 wt. %to about 3.0 wt. %, by weight of the polyol premix composition.

The polyol premix composition may optionally contain a non-siliconesurfactant, such as a non-silicone, non-ionic surfactant. Such mayinclude oxyethylated alkylphenols, oxyethylated fatty alcohols, paraffinoils, castor oil esters, ricinoleic acid esters, turkey red oil,groundnut oil, paraffins and fatty alcohols. A preferred non-siliconenon-ionic surfactant is LK-443 which is commercially available from AirProducts Corporation. When a non-silicone, non-ionic surfactant used, itis usually present in the polyol premix composition in an amount of fromabout 0.25 wt. % to about 3.0 wt. %, preferably from about 0.5 wt. % toabout 2.5 wt. %, and more preferably from about 0.75 wt. % to about 2.0wt. %, by weight of the polyol premix composition.

The inventive polyol premix composition next contains a catalyst whichis an adduct of an amine and an organic acid. In one embodiment, theamine has the formula R₁R₂N-[A-NR₃]_(n)R₄ wherein each of R₁, R₂, R₃,andR₄ is independently H, a C₁ to C₈ alkyl group, a C₁ to C₈ alkenyl group,C₁ to C₈ alcohol group, or a C₁ to C₈ ether group, or R₁ and R₂ togetherform a C₅ to C₇ cyclic alkyl group, a C₅ to C₇ cyclic alkenyl group, aC₅ to C₇ heterocyclic alkyl group, or a C₅ to C₇ heterocyclic alkenylgroup; A is a C₁ to C₅ alkyl group, a C₁ to C₅ alkenyl group, or anether; n is 0, 1, 2, or 3.

Preferably the amine is a sterically hindered amine. Useful are primaryamine, secondary amine or tertiary amine. Useful tertiary aminecatalysts non-exclusively include dicyclohexylmethylamine;ethyldiisopropylamine; dimethylcyclohexylamine; dimethylisopropylamine;methylisopropylbenzylamine; methylcyclopentylbenzylamine;isopropyl-sec-butyl-trifluoroethylamine; diethyl-(α-phenylethyl)amine,tri-n-propylamine, or combinations thereof. Useful secondary aminecatalysts non-exclusively include dicyclohexylamine;t-butylisopropylamine; di-t-butylamine; cyclohexyl-t-butylamine;di-sec-butylamine, dicyclopentylamine; di-(α-trifluoromethylethyl)amine;di-(α-phenylethyl)amine; or combinations thereof. Useful primary aminecatalysts non-exclusively include: triphenylmethylamine and1,1-diethyl-n-propylamine.

Other useful amines include morpholines, imidazoles, ether containingcompounds, and the like. These include

-   dimorpholinodiethylether-   N-ethylmorpholine-   N-methylmorpholine-   bis(dimethylaminoethyl) ether-   imidizole-   n-methylimidazole-   1,2-dimethylimidazole-   dimorpholinodimethylether-   N,N,N′,N′,N″,N″-pentamethyldiethylenetriamine-   N,N,N′,N′,N″,N″-pentaethyldiethylenetriamine-   N,N,N′,N′,N″,N″-pentamethyldipropylenetriamine-   bis(diethylaminoethyl) ether-   bis(dimethylaminopropyl) ether.

Useful organic acids non-exclusively include a carboxylic acid,dicarboxylic acid, phosphinic acid, phosphonic acid, sulfonic acid,sulfonic acid, sulfamic acid, hydroxamic acid, or combinations thereof.Examples of these organic acids non-exclusively include formic, acetic,propionic, butyric, caproic, isocaprotic, 2-ethylhexanoic, caprylic,cyanoacetic pyruvic, benzoic, oxalic, malonic, succinic, adipic,azelaic, trifluoroacetic, methanesulfonic, benzenesulfonic acid, and thelike and mixtures thereof. A preferred group comprises acetic, caprotic,isocaprotic, and 2-ethylhexanoic acid, and combinations thereof. Theacid reacts with the amine to form an adduct catalyst which has a lowerreactivity toward certain blowing agents, such as hydrohaloolefinsincluding HFO-1234ze and HFCO-1233zd, compared to a catalysts which isthe amine alone. The adduct is formed by pre-reacting the amine and theorganic acid prior to inclusion of the resulting adduct in the polyolpremix composition. In the usual case, sufficient organic acid isreacted with the selected amine to fully react with the amine. This isusually at least a stoichiometric amount of organic acid for thequantity of amine. Alternatively, the amine and organic acid can beadded to the polyol separately, forming the adduct in-situ, prior to theintroduction of the blowing agent into the polyol premix.

The amine-organic acid adduct catalyst is usually present in the polyolpremix composition in an amount of from about 0.2 wt. % to about 8.0 wt.%, preferably from about 0.4 wt. % to about 7.0 wt. %, and morepreferably from about 0.7 wt. % to about 6.0 wt. %, by weight of thepolyol premix composition.

The polyol premix composition may optionally further comprise anon-amine catalyst. Suitable non-amine catalysts may comprise anorganometallic compound containing bismuth, lead, tin, titanium,antimony, uranium, cadmium, cobalt, thorium, aluminum, mercury, zinc,nickel, cerium, molybdenum, vanadium, copper, manganese, zirconium,sodium, potassium, or combinations thereof. These non-exclusivelyinclude bismuth nitrate, lead 2-ethylhexoate, lead benzoate, ferricchloride, antimony trichloride, antimony glycolate, stannous salts ofcarboxylic acids, zinc salts of carboxylic acids, dialkyl tin salts ofcarboxylic acids, potassium acetate, potassium octoate, potassium2-ethylhexoate, glycine salts, quaternary ammonium carboxylates, alkalimetal carboxylic acid salts, andN-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate, tin (II)2-ethylhexanoate, dibutyltin dilaurate, or combinations thereof. Whenthe optional non-amine catalyst is used, it is usually present in thepolyol premix composition in an amount of from about 0.01 wt. % to about2.5 wt. %, preferably from about 0.05 wt. % to about 2.25 wt. %, andmore preferably from about 0.10 wt. % to about 2.00 wt. %. by weight ofthe polyol premix composition. While these are usual amounts, thequantity amount of metallic catalyst can vary widely, and theappropriate amount can be easily be determined by those skilled in theart.

The preparation of polyurethane or polyisocyanurate foams using thecompositions described herein may follow any of the methods well knownin the art can be employed, see Saunders and Frisch, Volumes I and IIPolyurethanes Chemistry and technology, 1962, John Wiley and Sons, NewYork, N.Y. or Gum, Reese, Ulrich, Reaction Polymers, 1992, OxfordUniversity Press, New York, N.Y. or Klempner and Sendijarevic, PolymericFoams and Foam Technology, 2004, Hanser Gardner Publications,Cincinnati, Ohio. In general, polyurethane or polyisocyanurate foams areprepared by combining an isocyanate, the polyol premix composition, andother materials such as optional flame retardants, colorants, or otheradditives. These foams can be rigid, flexible, or semi-rigid, and canhave a closed cell structure, an open cell structure or a mixture ofopen and closed cells.

It is convenient in many applications to provide the components forpolyurethane or polyisocyanurate foams in pre-blended formulations. Mosttypically, the foam formulation is pre-blended into two components. Theisocyanate and optionally other isocyanate compatible raw materialscomprise the first component, commonly referred to as the “A” component.The polyol mixture composition, including surfactant, catalysts, blowingagents, and optional other ingredients comprise the second component,commonly referred to as the “B” component. In any given application, the“B” component may not contain all the above listed components, forexample some formulations omit the flame retardant if flame retardancyis not a required foam property. Accordingly, polyurethane orpolyisocyanurate foams are readily prepared by bringing together the Aand B side components either by hand mix for small preparations and,preferably, machine mix techniques to form blocks, slabs, laminates,pour-in-place panels and other items, spray applied foams, froths, andthe like. Optionally, other ingredients such as fire retardants,colorants, auxiliary blowing agents, water, and even other polyols canbe added as a stream to the mix head or reaction site. Mostconveniently, however, they are all incorporated into one B component asdescribed above.

A foamable composition suitable for forming a polyurethane orpolyisocyanurate foam may be formed by reacting an organicpolyisocyanate and the polyol premix composition described above. Anyorganic polyisocyanate can be employed in polyurethane orpolyisocyanurate foam synthesis inclusive of aliphatic and aromaticpolyisocyanates. Suitable organic polyisocyanates include aliphatic,cycloaliphatic, araliphatic, aromatic, and heterocyclic isocyanateswhich are well known in the field of polyurethane chemistry. These aredescribed in, for example, U.S. Pat. Nos. 4,868,224; 3,401,190;3,454,606; 3,277,138; 3,492,330; 3,001,973; 3,394,164; 3,124,605; and3,201,372. Preferred as a class are the aromatic polyisocyanates.

Representative organic polyisocyanates correspond to the formula:R(NCO)zwherein R is a polyvalent organic radical which is either aliphatic,aralkyl, aromatic or mixtures thereof, and z is an integer whichcorresponds to the valence of R and is at least two. Representative ofthe organic polyisocyanates contemplated herein includes, for example,the aromatic diisocyanates such as 2,4-toluene diisocyanate, 2,6-toluenediisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate, crudetoluene diisocyanate, methylene diphenyl diisocyanate, crude methylenediphenyl diisocyanate and the like; the aromatic triisocyanates such as4,4′,4″-triphenylmethane triisocyanate, 2,4,6-toluene triisocyanates;the aromatic tetraisocyanates such as4,4′-dimethyldiphenylmethane-2,2′5,5-′tetraisocyanate, and the like;arylalkyl polyisocyanates such as xylylene diisocyanate; aliphaticpolyisocyanate such as hexamethylene-1,6-diisocyanate, lysinediisocyanate methylester and the like; and mixtures thereof Otherorganic polyisocyanates include polymethylene polyphenylisocyanate,hydrogenated methylene diphenylisocyanate, m-phenylene diisocyanate,naphthylene-1,5-diisocyanate, 1-methoxyphenylene-2,4-diisocyanate,4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenyldiisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, and3,3′-dimethyldiphenylmethane-4,4′-diisocyanate; Typical aliphaticpolyisocyanates are alkylene diisocyanates such as trimethylenediisocyanate, tetramethylene diisocyanate, and hexamethylenediisocyanate, isophorene diisocyanate, 4,4′-methylenebis(cyclohexylisocyanate), and the like; typical aromatic polyisocyanates include m-,and p-phenylene disocyanate, polymethylene polyphenyl isocyanate, 2,4-and 2,6-toluenediisocyanate, dianisidine diisocyanate, bitoyleneisocyanate, naphthylene 1,4-diisocyanate,bis(4-isocyanatophenyl)methene, bis(2-methyl-4-isocyanatophenyl)methane,and the like. Preferred polyisocyanates are the polymethylene polyphenylisocyanates, Particularly the mixtures containing from about 30 to about85 percent by weight of methylenebis(phenyl isocyanate) with theremainder of the mixture comprising the polymethylene polyphenylpolyisocyanates of functionality higher than 2. These polyisocyanatesare prepared by conventional methods known in the art. In the presentinvention, the polyisocyanate and the polyol are employed in amountswhich will yield an NCO/OH stoichiometric ratio in a range of from about0.9 to about 5.0. In the present invention, the NCO/OH equivalent ratiois, preferably, about 1.0 or more and about 3.0 or less, with the idealrange being from about 1.1 to about 2.5. Especially suitable organicpolyisocyanate include polymethylene polyphenyl isocyanate, methylenebis(phenyl isocyanate), toluene diisocyanates, or combinations thereof.

In the preparation of polyisocyanurate foams, trimerization catalystsare used for the purpose of converting the blends in conjunction withexcess A component to polyisocyanurate-polyurethane foams. Thetrimerization catalysts employed can be any catalyst known to oneskilled in the art, including, but not limited to, glycine salts,tertiary amine trimerization catalysts, quaternary ammoniumcarboxylates, and alkali metal carboxylic acid salts and mixtures of thevarious types of catalysts. Preferred species within the classes arepotassium acetate, potassium octoate, andN-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate.

Conventional flame retardants can also be incorporated, preferably inamount of not more than about 20 percent by weight of the reactants.Optional flame retardants include tris(2-chloroethyl)phosphate,tris(2-chloropropyl)phosphate, tris(2,3-dibromopropyl)phosphate,tris(1,3-dichloropropyl)phosphate, tri(2-chloroisopropyl)phosphate,tricresyl phosphate, tri(2,2-dichloroisopropyl)phosphate, diethylN,N-bis(2-hydroxyethyl) aminomethylphosphonate, dimethylmethylphosphonate, tri(2,3-dibromopropyl)phosphate,tri(1,3-dichloropropyl)phosphate, and tetra-kis-(2-chloroethyl)ethylenediphosphate, triethylphosphate, diammonium phosphate, varioushalogenated aromatic compounds, antimony oxide, aluminum trihydrate,polyvinyl chloride, melamine, and the like. Other optional ingredientscan include from 0 to about 7 percent water, which chemically reactswith the isocyanate to produce carbon dioxide. This carbon dioxide actsas an auxiliary blowing agent. Formic acid is also used to producecarbon dioxide by reacting with the isocyanate and is optionally addedto the “B” component. In addition to the previously describedingredients, other ingredients such as, dyes, fillers, pigments and thelike can be included in the preparation of the foams. Dispersing agentsand cell stabilizers can be incorporated into the present blends.Conventional fillers for use herein include, for example, aluminumsilicate, calcium silicate, magnesium silicate, calcium carbonate,barium sulfate, calcium sulfate, glass fibers, carbon black and silica.The filler, if used, is normally present in an amount by weight rangingfrom about 5 parts to 100 parts per 100 parts of polyol. A pigment whichcan be used herein can be any conventional pigment such as titaniumdioxide, zinc oxide, iron oxide, antimony oxide, chrome green, chromeyellow, iron blue siennas, molybdate oranges and organic pigments suchas para reds, benzidine yellow, toluidine red, toners andphthalocyanines.

The polyurethane or polyisocyanurate foams produced can vary in densityfrom about 0.5 pounds per cubic foot to about 60 pounds per cubic foot,preferably from about 1.0 to 20.0 pounds per cubic foot, and mostpreferably from about 1.5 to 6.0 pounds per cubic foot. The densityobtained is a function of how much of the blowing agent or blowing agentmixture disclosed in this invention plus the amount of auxiliary blowingagent, such as water or other co-blowing agents is present in the Aand/or B components, or alternatively added at the time the foam isprepared. These foams can be rigid, flexible, or semi-rigid foams, andcan have a closed cell structure, an open cell structure or a mixture ofopen and closed cells. These foams are used in a variety of well knownapplications, including but not limited to thermal insulation,cushioning, flotation, packaging, adhesives, void filling, crafts anddecorative, and shock absorption.

The following non-limiting examples serve to illustrate the invention.

EXAMPLE 1

To determine the effect of an acid on the production of fluoride ion, atest mixture of 20 mL methanol, 0.28 g water, 1.01 g triethylamine, 0.35g Niax L6900, 1.78 g 1,3,3,3-tetrafluoropropene, and 1.16 g4-methylpentanoic acid (1 molar equivalent relative to triethylamine)was heated in a glass pressure bottle at 120 F for 70 hours. At the endof the heating period, the liquid phase was analyzed for fluoride. Thefluoride content was less than one-tenth of the amount formed in theabsence of 4-methylpentanoic acid.

EXAMPLE 2 (COMPARATIVE EXAMPLE)

A polyol (B Component) formulation was made up of 100 parts by weight ofa polyol blend, 1.5 parts by weight Niax L6900 silicone surfactant, 1.5parts by weight water, 1.2 parts by weightN,N,N′,N′,N″,N″-pentamethyldiethylenetriamine (sold as Polycat 5 by AirProducts and Chemicals) catalyst, 5.6 parts by weight ofcis-1,3,3,3-tetrafluoropropene, 0.7 parts by weighttrans-1,3,3,3-tetrafluoropropene and 1.7 parts by weight of1,1,1,3,3-pentafluoropropane blowing agent. The total B componentcomposition, when freshly prepared and combined with 120.0 parts byweight of Lupranate M20S polymeric isocyanate yielded a good qualityfoam with a fine and regular cell structure. Foam reactivity was typicalfor a pour in place foam with a gel time of 78 seconds. The total B-sidecomposition (112.2 parts) was then aged at 120° F. for 62 hours, andthen combined with 120.0 parts of M20S Iso polyisocyanate to make afoam. The foam was very poor in appearance with total cell collapse. Geltime could not be determined due to the cell collapse. Significantyellowing was noted during aging.

EXAMPLE 3 Foam Tests

A polyol (B Component) formulation was made up of 100 parts by weight ofa polyol blend, 1.5 parts by weight Niax L6900 silicone surfactant, 1.5parts by weight water, 1.2 parts by weightN,N,N′,N′,N″,N″-pentamethyldiethylenetriamine (sold as Polycat 5 by AirProducts and Chemicals) catalyst, 2.4 parts by weight of isocaproicacid, and 5.6 parts by weight of cis-1,3,3,3-tetrafluoropropene, 0.7parts by weight trans-1,3,3,3-tetrafluoropropene, and 1.7 parts byweight of 1,1,1,3,3-pentafluoropropane blowing agent. The total Bcomponent composition, when freshly prepared and combined with 120.0parts by weight of Lupranate M20S polymeric isocyanate yielded a goodquality foam with a fine and regular cell structure. Foam reactivity wastypical for a pour in place foam with a gel time of 105 seconds. Thetotal B-side composition (114.6 parts) was then aged at 120° F. for 62hours, and then combined with 120.0 parts of M20S Iso polyisocyanate tomake a foam. The foam was normal in appearance without cell collapse.Gel time was 150 seconds. Some yellowing was noted during aging.

While the present invention has been particularly shown and describedwith reference to preferred embodiments, it will be readily appreciatedby those of ordinary skill in the art that various changes andmodifications may be made without departing from the spirit and scope ofthe invention. It is intended that the claims be interpreted to coverthe disclosed embodiment, those alternatives which have been discussedabove and all equivalents thereto.

What is claimed is:
 1. A polyol premix composition that has been agedwhich comprises a combination of: (a) from about 1 wt % to about 30 wt %of a blowing agent, (b) from about 60 wt. % to about 95 wt. % of apolyol, (c) from about 0.5 wt. % to about 5.0 wt. % of a siliconesurfactant, and (d) from about 0.2 wt. % to about 8.0 wt. % of acatalyst which catalyst is an adduct of a tertiary amine and an organicacid comprising acetic acid or formic acid, wherein the blowing agentcomprises: (i) from about 10 wt % to about 70 wt % of a hydrohaloolefinbased on the weight of the blowing agent, wherein said hydrohaloolefinis selected from the group consisting oftrans-1,3,3,3-tetrafluoropropene, trans-1-chloro-3,3,3-trifluoropropene,and combinations thereof, and (ii) an auxiliary blowing agent selectedfrom the group consisting of hydrocarbon, fluorocarbon, chlorocarbon,fluorochlorocarbon, halogenated hydrocarbon, ethers, esters, aldehydes,ketones, halogenated ethers, CO₂ generating material, or combinationsthereof, wherein the catalyst and the hydrohaloolefin blowing agentexhibit sufficiently reduced reactivity with each other, as compared toa composition comprising the blowing agent and catalyst that is not anadduct of an amine and an organic acid, such that foam formed from thepolyol premix composition exhibits substantially no cell collapse aftersaid premix has been aged at 120° F. for 62 hours.
 2. The polyol premixcomposition of claim 1 wherein the organic acid comprises acetic acid orformic acid and the blowing agent comprisestrans-1-chloro-3,3,3-trifluoropropene.
 3. The polyol premix compositionof claim 1 wherein the hydrohaloolefin comprisestrans-1,3,3,3-tetrafluoropropene.
 4. The polyol premix composition ofclaim 1 wherein the hydrohaloolefin comprisestrans-1-chloro-3,3,3-trifluoropropene.
 5. The polyol premix compositionof claim 1 wherein said auxiliary blowing agent further comprises:water, formic acid, organic acids that produce CO₂ when they react withan isocyanate, hydrocarbons; ethers, esters, aldehydes, ketones,halogenated ethers; pentafluorobutane; pentafluoropropane;hexafluoropropane; heptafluoropropane; trans-1,2 dichloroethylene;methyl formate; 1-chloro-1,2,2,2-tetrafluoroethane;1,1-dichloro-1-fluoroethane; 1,1,1,2-tetrafluoroethane;1,1,1,2-tetrafluoroethane; 1-chloro 1,1-difluoroethane;1,1,1,3,3-pentafluorobutane; 1,1,1,2,3,3,3-heptafluoropropane;trichlorofluoromethane; dichlorodifluoromethane;1,1,1,3,3,3-hexafluoropropane; 1,1,1,2,3,3-hexafluoropropane;difluoromethane; difluoroethane; 1,1,1,3,3-pentafluoropropane;1,1-difluoroethane; isobutane; normal pentane; isopentane; cyclopentane,or combinations thereof.
 6. The polyol premix composition of claim 1wherein the silicone surfactant comprises a polysiloxane polyoxyalkyleneblock co-polymer.
 7. The polyol premix composition of claim 1 furthercomprising a non-silicone, non-ionic surfactant.
 8. The polyol premixcomposition of claim 1 wherein the polyol comprises one or more of asucrose containing polyol; phenol; a phenol formaldehyde containingpolyol; a glucose containing polyol; a sorbitol containing polyol; amethylglucoside containing polyol; an aromatic polyester polyol;glycerol; ethylene glycol; diethylene glycol; propylene glycol; graftcopolymers of polyether polyols with a vinyl polymer; a copolymer of apolyether polyol with a polyurea; one or more of (a) condensed with oneor more of (b): (a) glycerine, ethylene glycol, diethylene glycol,trimethylolpropane, ethylene diamine, pentaerythritol, soy oil,lecithin, tall oil, palm oil, castor oil; (b) ethylene oxide, propyleneoxide, a mixture of ethylene oxide and propylene oxide; or combinationsthereof.
 9. The polyol premix composition of claim 1 wherein thetertiary amine comprises cyclohexyldimethylamine;dicyclohexylmethylamine; ethyldiisopropylamine; dimethylcyclohexylamine;dimethylisopropylamine; methylisopropylbenzylamine;methylcyclopentylbenzylamine; isopropyl-sec-butyl-trifluoroethylamine;diethyl-(α-phenylethyl)amine, tri-n-propylamine; or combinationsthereof.
 10. The polyol premix composition of claim 1 further comprisinga catalyst comprising an organometallic compound containing bismuth,lead, tin, titanium, antimony, uranium, cadmium, cobalt, thorium,aluminum, mercury, zinc, nickel, cerium, molybdenum, vanadium, copper,manganese, zirconium, potassium, sodium, or combinations thereof. 11.The polyol premix composition of claim 1 further comprising a catalystcomprising bismuth nitrate, lead 2-ethylhexoate, lead benzoate, ferricchloride, antimony trichloride, antimony glycolate, stannous salts ofcarboxylic acids, zinc salts of carboxylic acids, dialkyl tin salts ofcarboxylic acids, glycine salts, tertiary amine trimerization catalysts,quaternary ammonium carboxylates, alkali metal carboxylic acid salts,potassium acetate, potassium octoate, potassium 2-ethylhexanoate,N-(2-hydroxy-5-nonylphenol)methyl-N-methylglycinate, tin (II)2-ethylhexanoate, dibutyltin dilaurate, or combinations thereof.
 12. Afoamable composition comprising a mixture of an organic polyisocyanateand the polyol premix composition of claim
 1. 13. The foamablecomposition of claim 12 wherein the organic polyisocyanate comprises apolymethylene polyphenyl isocyanate, methylenebis(phenyl isocyanate),toluene diisocyanate, or combinations thereof.
 14. The polyol premixcomposition of claim 1 wherein the catalyst and blowing agent exhibitreduced decomposition of the blowing agent over a period of time, ascompared to a composition comprising a blowing agent and catalyst thatis not an adduct of an amine and an organic acid.
 15. A method offorming an aged polyol premix composition which comprises: forming apolyol premix by combining (a) from about 1 wt % to about 30 wt % of ablowing agent, (b) from about 60 wt. % to about 95 wt. % of a polyol,(c) from about 0.5 wt. % to about 5.0 wt. % of a silicone surfactant,and (d) from about 0.2 wt. % to about 8.0 wt. % of a catalyst whichcatalyst is an adduct of a tertiary amine and an organic acid comprisingacetic acid or formic acid, wherein the blowing agent comprises (i) fromabout 10 wt % to about 70 wt % of a hydrohaloolefin based on the weightof the blowing agent, wherein said hydrohaloolefin is selected from thegroup consisting of trans-1,3,3,3-tetrafluoropropene,trans-1-chloro-3,3,3-trifluoropropene, and combinations thereof, and(ii) an auxiliary blowing agent selected from the group consisting ofhydrocarbon, fluorocarbon, chlorocarbon, fluorochlorocarbon, halogenatedhydrocarbon, ethers, esters, aldehydes, ketones, halogenated ethers, CO₂generating material, or combinations thereof, and storing said premixafter said formation, such that foam formed from the polyol premixcompositon exhibits substantially no cell collapse after said premix hasbeen aged at 120° F. for 62 hours.
 16. A method of preparing apolyurethane or polyisocyanurate foam comprising (A) providing a polyolpremix composition that has been aged, said polyol premix compositioncomprising a combination of: (a) from about 1 wt % to about 30 wt % of ablowing agent, (b) from about 60 wt. % to about 95 wt. % of a polyol,(c) from about 0.5 wt. % to about 5.0 wt. % of a silicone surfactant,and (d) from about 0.2 wt. % to about 8.0 wt. % of a catalyst whichcatalyst is an adduct of a tertiary amine and an organic acid comprisingacetic acid or formic acid, wherein the blowing agent comprises: (i)from about 10 wt % to about 70 wt % of a hydrohaloolefin based on theweight of the blowing agent, wherein said hydrohaloolefin is selectedfrom the group consisting of trans-1,3,3,3-tetrafluoropropene,trans-1-chloro-3,3,3-trifluoropropene, and combinations thereof, and(ii) an auxiliary blowing agent selected from the group consisting ofhydrocarbon, fluorocarbon, chlorocarbon, fluorochlorocarbon, halogenatedhydrocarbon, ethers, esters, aldehydes, ketones, halogenated ethers, CO₂generating material, or combinations thereof, wherein the catalyst andthe hydrohaloolefin blowing agent exhibit sufficiently reducedreactivity with each other, as compared to a composition comprising theblowing agent and catalyst that is not an adduct of an amine and anorganic acid; and forming a foam by reacting an organic polyisocyanatewith the aged polyol premix composition from said providing step,wherein said foam exhibits substantially no cell collapse after saidpremix has been aged at 120° F. for 62 hours.
 17. A foam producedaccording to the method of claim
 16. 18. A polyol premix compositionthat has been aged which comprises a combination of: (a) from about 1 wt% to about 30 wt % of blowing agent, (b) from about 60 wt. % to about 95wt. % of a polyol, (c) from about 0.5 wt. % to about 5.0 wt. % of asilicone surfactant, and (d) from about 0.2 wt. % to about 8.0 wt. % ofa catalyst which catalyst is an adduct of an amine and an organic acid,wherein the blowing agent comprises: (i) from about 10 wt % to about 70wt % of a hydrohaloolefin based on the weight of the blowing agent,wherein said hydrohaloolefin is selected from the group consisting of1,3,3,3-tetrafluoropropene and 1-chloro-3,3,3-trifluoropropene andcombinations of these and (ii) an auxiliary blowing agent selected fromthe group consisting of hydrocarbon, fluorocarbon, chlorocarbon,fluorochlorocarbon, halogenated hydrocarbon, ethers, esters, aldehydes,ketones, halogenated ethers, CO₂ generating material, or combinationsthereof, wherein the amine is selected from the group consisting ofN,N,N′,N′,N″,N″-pentamethyldiethylenetriamine,N,N,N′,N′,N″,N″-pentaethyldiethylenetriamine,N,N,N′,N′,N″,N″-pentamethyldipropylenetriamine,N,N-dimethylcyclohexylamine and combinations thereof, and wherein theorganic acid is acetic acid or formic acid, such that foam formed fromthe polyol premix compositon exhibits substantially no cell collapseafter said premix has been aged at 120° F. for 62 hours.
 19. The polyolpremix composition of claim 18 wherein the blowing agent comprisestrans-1,3,3,3-tetrafluoropropene, the amine comprisesN,N,N′,N′,N″,N″-pentamethyldiethylenetriamine orN,N-dimethylcyclohexylamine and the organic acid comprises formic acidor acetic acid.
 20. The polyol premix composition of claim 18 whereinthe blowing agent comprises trans-1-chloro-3,3,3-trifluoropropene, theamine comprises N,N,N′,N′,N″,N″-pentamethyldiethylenetriamine orN,N-dimethylcyclohexylamine and the organic acid comprises formic acidor acetic acid.